This invention relates to electrical plugs, and, in particular, to an electrical plug with a removable fuse.
The benefits of putting a fuse in an electrical plug have been known for some time. The plug is usually the most accessible part of an electrical appliance, so putting a fuse in the plug puts it in a convenient location for insertion and replacement of the fuse. Also, if a fuse is located in the plug of a cord set, it can provide the protection of a fuse to any electrical machine or appliance to which the cord set is attached. In addition, putting a fuse in the plug end of a cord set avoids the problem of overloading the cord in the event of mismatching the cord to the appliance.
When a fuse is put into an electrical plug, it is important to provide for easy removal and replacement of the fuse. It is also important that there be good electrical contact to and from the fuse, that the elements of the construction be sound and not prone to failure, and that the construction be inexpensive to manufacture.
In previous constructions in which one of the male electrical connectors is used as a handle for insertion and removal of the fuse, there is a spring inside the body of the plug for urging the fuse into electrical contact and for ejecting the fuse from the plug when removal of the fuse is necessary. The spring inside the body of the plug is an additional part which increases the complication in installation, increases the expense of manufacture, and which may be lost upon removal of the fuse from the plug. In addition, the constructions which made use of a spring have provided a relatively small surface contact area between the fuse and the interior of the plug body, thereby increasing the chance of problems due to faulty electrical contact.